$J$ $K$ $L$ If: $ JL = 39$, $ KL = 5x + 2$, and $ JK = 2x + 9$, Find $KL$.
From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {2x + 9} + {5x + 2} = {39}$ Combine like terms: $ 7x + 11 = {39}$ Subtract $11$ from both sides: $ 7x = 28$ Divide both sides by $7$ to find $x$ $ x = 4$ Substitute $4$ for $x$ in the expression that was given for $KL$ $ KL = 5({4}) + 2$ Simplify: $ {KL = 20 + 2}$ Simplify to find ${KL}$ : $ {KL = 22}$